DE112013004096T5 - Control system for a hybrid vehicle - Google Patents

Abstract

In a control system for a hybrid vehicle including an internal combustion engine, a motor-generator (MG1), a power distribution / integration mechanism having three rotary elements provided with a crankshaft, a rotary shaft of the motor-generator (MG1), and a ring gear shaft connected, having a motor-generator (MG2) and a battery, a battery ECU under a condition that the vehicle speed (V) is lower than a predetermined speed (V1), a required charging power (Pchg) to a required charging power (Pchg_α) which is lower than a normally set required charging power (Pchg_β), so that a torque fluctuation of the engine is absorbed by a hysteresis torque generated by a hysteresis mechanism.

Description

BACKGROUND OF THE INVENTION

1. Field of the invention

The invention relates to a control system which is used in a so-called hybrid vehicle on which an internal combustion engine and at least one electric motor are installed as drive sources.

2. Description of the Related Art

A known example of this type of hybrid vehicle includes a planetary gear mechanism having three rotary elements coupled to a drive shaft coupled to an axle, an output shaft of an engine and a rotary shaft of a motor generator MG1, and a motor generator MG2 capable of is to generate power for the drive shaft (see, for example, Japanese Patent Publication No. 2009-248913 ( JP 2009-248913 A )). In the hybrid vehicle, a damper that absorbs torque fluctuation is provided between the engine and the planetary gear mechanism.

In the hybrid vehicle described above, when the remaining capacity of the battery decreases, the engine may be operated to the battery in a region where the rotational speed is low and the torque is high, and it is likely that vibrations and abnormal noises are generated to load. At this time, when the vehicle speed is low, the vibrations and abnormal noises caused by the operation of the engine in the region where the engine speed is low and the engine torque is high are not masked by vibrations and abnormal sounds caused by driving the vehicle are effected; therefore, the electric power for charging the battery is restricted to a low level, so that the engine is prevented from being operated in the region where the rotational speed is low and the torque is high.

SUMMARY OF THE INVENTION

In the in JP 2009-248913 A In the hybrid vehicle described above, vibrations are suppressed by absorbing torque fluctuations of the engine by applying a hysteresis torque to the damper. However, it is not considered at all to set the required charging power with respect to its relationship with the hysteresis torque of the damper.

Thus, when the required charging power with which the hysteresis torque can not be applied is generated, the torque fluctuation of the engine is directly transmitted to the planetary gear mechanism, and the vibration and abnormal noise suppression performance can be lowered.

More specifically, for example, if the required charging power is set to a high level when the hybrid vehicle changes from the EV traveling mode to the engine traveling mode, the amount of change of the required charging power becomes large, and the fluctuation range of the engine torque becomes large, making it more likely that the driver perceives the vibrations and abnormal noises.

The invention provides a control system for a hybrid vehicle that exhibits improved performance in suppressing vibrations and abnormal noises generated by the operation of an internal combustion engine under vehicle driving conditions under which the driver is likely to absorb the vibrations and perceives abnormal sounds.

A control system for a hybrid vehicle according to the invention includes an internal combustion engine, a generator, a planetary gear mechanism, an electric motor, a power storage device, a damper device, a detector, and an electronic control unit. The generator receives power or generates power. The planetary gear mechanism has three rotary elements connected to an output shaft of the internal combustion engine, a rotary shaft of the generator, and a drive shaft connected to drive wheels, respectively. The electric motor receives power from the drive shaft or generates power for the drive shaft. The power storage device supplies and receives electric power to and from the generator and the electric motor. The damper device is disposed in a power transmission path between the internal combustion engine and the planetary gear mechanism. The damper device has a hysteresis mechanism which generates a hysteresis torque with frictional force generated from a friction material. The detector detects a vehicle speed of the hybrid vehicle. The electronic control unit is configured to set a required electric power necessary to charge the power storage device based on a state of charge of the power storage device. The electronic control unit is configured to reduce the required electric power when the vehicle speed detected by the detector is lower, so that a rotational fluctuation of the output shaft of the vehicle Internal combustion engine is absorbed by the hysteresis generated by the hysteresis mechanism.

With the described arrangement, the control system according to the invention reduces the required charging power when the vehicle speed is lower, so that a rotational fluctuation of the output shaft of the internal combustion engine is absorbed by the hysteresis torque generated by the hysteresis mechanism. Thus, it is possible to lower a torque generated by the internal combustion engine in a region in which the rotational speed is low and the torque is high, and in which it is likely that the rotational fluctuation is transmitted to the planetary gear mechanism. Therefore, in the region where the vehicle speed is low, the control system according to the invention makes it possible to apply a hysteresis torque against the rotation fluctuation. Thus, the control system according to the invention provides improved performance in suppressing vibrations and abnormal noises generated by the operation of the internal combustion engine in comparison with the known system, under driving conditions under which the driver is likely to experience the vibrations and abnormal ones Perceives noises.

In the control system described above, the hysteresis mechanism may include a first hysteresis generating section that generates a first hysteresis torque depending on a torsional angle of the damper device and a second hysteresis generating section that generates a second hysteresis torque greater than the first hysteresis torque depending on the torsional angle and the electronic hysteresis torque The control unit may be configured to reduce the required electric power when the vehicle speed detected by the detector is lower, so that the rotational fluctuation is absorbed by the first hysteresis torque generated by the first hysteresis generation section.

With the above-described structure, the control system according to the invention reduces the required charging power when the vehicle speed is lower, so that a rotational fluctuation of the output shaft of the internal combustion engine is absorbed by the first hysteresis torque smaller than the second hysteresis torque; therefore, in the region where the vehicle speed is low, the first hysteresis torque may be applied against the rotational fluctuation. Also, in the case where the damper device takes the form of a so-called two-stage hysteresis damper which generates a first hysteresis torque and a second hysteresis torque depending on the torsion angle, the control system according to the invention thus provides improved performance in suppressing vibrations and abnormal noises be caused by the operation of the internal combustion engine, under driving conditions under which it is likely that the driver perceives the vibrations and abnormal noises.

In the control system described above, the electronic control unit may be configured to calculate a required driving force required by the hybrid vehicle, and the electronic control unit may be configured to reduce the required electric power when the calculated required driving force becomes lower is such that the rotational fluctuation is absorbed by the first hysteresis torque generated by the first hysteresis generation section.

With the arrangement described above, the control system according to the invention reduces the required charging power when the required driving force is smaller, so that a rotational fluctuation of the output shaft of the internal combustion engine is absorbed by the first hysteresis torque smaller than the second hysteresis torque; therefore, the torque generated by the internal combustion engine can be reduced in a region where the required driving force is small and it is likely that the rotational fluctuation is transmitted to the planetary gear mechanism. Thus, in the control system according to the invention, the first hysteresis torque in the region where the required driving force is small can be applied against the rotational fluctuation. Thus, the control system according to the invention provides an improved performance in suppression of vibrations and abnormal noises generated by the operation of the internal combustion engine compared to the known system under driving conditions under which the driver is likely to experience the vibrations and abnormal ones Perceives noises.

According to the invention, the control system for a hybrid vehicle provides improved performance in suppressing vibrations and abnormal noises generated by the operation of the internal combustion engine under driving conditions under which the driver is likely to perceive the vibrations and abnormal noises.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, advantages, and the technical and industrial significance of embodiments of the invention will be described below with reference to the accompanying drawings, in which: same numbers denote like elements, and in which:

1 Fig. 12 is a diagram showing the structure of a hybrid vehicle in which a vehicle control system according to a first embodiment of the invention is used;

2 Fig. 13 is a view showing a model of a two-stage hysteresis damper according to the first embodiment of the invention;

3 Fig. 12 is a cross-sectional view of the two-stage hysteresis damper according to the first embodiment of the invention;

4 Figure 4 is a graph showing the relationship between engine torque and required charging power and charging current, respectively;

5 Fig. 12 is a graph showing the relationship between the torsion angle of a known two-stage hysteresis damper and the engine torque;

6 Fig. 11 is a view showing a region in which a rattle is heard, which is defined as a parameter using the vehicle speed and the required driving force;

7 Fig. 10 is a flowchart showing a control for reducing the required charging power executed by an ECU according to the first embodiment of the invention;

8th Fig. 12 is a graph showing the relationship between the torsion angle of the two-stage hysteresis damper according to the first embodiment of the invention and the engine torque;

9 Fig. 10 is a flowchart showing a control for reducing the required charging power executed by an ECU according to the second embodiment of the invention; and

10 Fig. 10 is a flowchart showing a control for reducing the required charging power executed by an ECU according to the third embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Some embodiments of the invention will now be described with reference to the drawings.

With reference to 1 to 8th A control system for a vehicle according to a first embodiment of the invention will be described. The vehicle control system according to this embodiment is used in a so-called hybrid vehicle in which an internal combustion engine and at least one electric motor (or at least one generator) are installed as power sources for generating a driving force of the vehicle.

As in 1 is shown, the hybrid vehicle 1 an engine 2 , a power distribution / integration mechanism 3 , Motor Generators MG1, MG2, a reduction gear 4 , a battery 80 and a vehicle control system 10 on.

The vehicle control system (electronic control unit) 10 has a hybrid electronic vehicle control unit (hereinafter referred to simply as "HVECU") 100 , an electronic engine control unit (hereinafter referred to simply as "engine ECU") 200 , an electronic motor control unit (hereinafter referred to simply as "engine ECU") 300 and a battery control unit (hereinafter referred to simply as "battery ECU") 400 on. In this embodiment, the vehicle control system provides 10 the electronic control unit according to the invention ready.

The engine 2 is constructed as an internal combustion engine capable of producing power with a hydrocarbon-containing fuel, for example, gasoline or light oil. In the engine 2 For example, gasoline is injected from a fuel injection valve (not shown) and mixed with intake air so that a mixture of fuel and air is drawn into a combustion chamber of each cylinder. Then, the air-fuel mixture in the combustion chamber is detonated and burned, leaving a piston (not shown) in each cylinder of the engine 2 is added, with the combustion energy is pushed down, and the reciprocation of the piston is in a rotational movement of a crankshaft 27 the engine 2 transformed.

The engine 2 is from the engine ECU 200 controlled. Various sensors, such as a crank angle sensor and a water temperature sensor, are available with the engine ECU 200 connected. The engine ECU 200 calculates the engine speed based on, for example, a signal received from the crank angle sensor. The engine ECU 200 gives via an output port various control signals for driving the engine 2 including a drive signal to the fuel injection valve, a drive signal to a throttle motor that detects the opening of the Throttle controls, and a drive signal to an ignition coil.

The engine ECU 200 communicates with the HVECU 100 and controls the operation of the engine 2 according to a control signal from the HVECU 100 , The engine ECU 200 If necessary, also gives data regarding engine operating conditions 2 to the HVECU 100 out.

The power distribution / integration mechanism 3 is a three - shaft power distribution / integration mechanism via a damper device 70 with the crankshaft 27 connected is. The power distribution / integration mechanism 3 has a sun wheel 31 as externally toothed gear, a ring gear 32 as internally toothed gear concentric with the sun gear 31 is arranged two or more pinions 33 that with the sun wheel 31 and the ring gear 32 comb, and a carrier 34 on top of the two or more sprockets 33 so wear that pinion 33 can revolve around itself and also around the axis of the mechanism 3 rotate. That is, the power distribution / integration mechanism 3 is in the form of a planetary gear mechanism using the sun gear 31 , the ring gear 32 and the vehicle 34 as a rotary elements performs a differential operation. These three rotary elements are connected to three respective shafts, ie with a rotary shaft 36 a motor generator MG1 (which will be described later) with which the sun gear 31 can rotate as a unit, with a ring gear 32a as a drive shaft, which has a counter gear 35 and a transmission mechanism 60 with drive wheels 63a . 63b connected, and with the crankshaft 27 as the output shaft of the engine 2 ,

The carrier 34 is with him crankshaft 27 connected, and the sun wheel 31 is connected to the motor generator MG1. In addition, the ring gear 32 over the ring gear shaft 32a with the reduction gear 4 connected. The counter gear 35 is with the ring gear shaft 32a connected. The counter gear 35 meshes with the transmission mechanism 60 ,

When the motor generator MG1 functions as a generator, the power distribution / integration mechanism distributes 3 Power coming from the engine 2 is received over the carrier 34 to the side of the sun wheel 31 and to the side of the ring gear 32 , according to their teeth number ratio. On the other hand, when the motor generator MG1 functions as an electric motor, the power distribution / integration mechanism integrates or combines 3 Power coming from the engine 2 over the carrier 34 and power supplied by the motor generator MG1 via the sun gear 31 is received, and generates the resultant power to the side of the ring gear 32 , The power on the ring gear 32 is finally transmitted via the counter gear 35 , the gear mechanism 60 and the differential gear 62 to the drive wheels 63a . 63b delivered to the vehicle.

The reduction gear 4 has a sun wheel 41 , which is connected to the motor generator MG2, a ring gear 42 concentric with the sun wheel 41 is arranged two or more pinions 43 that with the sun wheel 41 and the ring gear 42 comb, and a carrier 44 on which has carrier waves, which the pinions 43 wear at the other ends so that the pinions 43 to be able to turn around yourself. The reduction gear 4 Provides a planetary gear mechanism that drives the sun 41 , the ring gear 42 and pinion 43 has as rotary elements, and serves to reinforce a drive torque by lowering the speed transmitted from the motor generator MG2.

When the motor generator MG2 functions as an electric motor, the reduction gear lowers 4 the rotational speed transmitted from the motor generator MG2 to boost the drive torque and supplies the torque to the ring gear 42 , By contrast, the reduction gear increases 4 the speed that is caused by power, that of the ring gear 42 is received to attenuate or reduce a driving torque, and outputs the torque from the sun gear 41 so that the motor generator MG2 serves as a generator.

The motor-generators MG1, MG2 are each constructed as a known synchronous motor-generator which functions as an electric motor, converts electric power supplied thereto into mechanical power, and also functions as a generator converting received mechanical power into electric power. That is, the motor-generators MG1, MG2 are each constructed as a generator and as an electric motor capable of generating and receiving power. The motor generator MG1 is mainly used as a generator, and the motor generator MG2 is mainly used as an electric motor. The motor generator MG <b> 1 of this embodiment provides the generator according to the invention, and the motor generator MG <b> 2 provides the electric motor according to the invention.

The motor-generators MG1, MG2 supply and receive electric power to and from the battery 80 each with inverter 81 . 82 , A power line 83 which the inverters 81 . 82 with the battery 80 connects, consists of a positive bus and a negative bus, that of the inverters 81 . 82 be used together. With this arrangement, electric power generated by one of the motor-generators MG <b> 1, MG <b> 2 can be supplied from the other motor-generator consumed. Accordingly, the battery 80 can be charged with electric power generated by one of the motor-generators MG1, MG2, and can deliver or supply electric power to each of the motor-generators MG1, MG2. When the amounts of electric power supplied to or received from the motor generator MG1 are equalized with those of the motor generator MG2, neither charging nor discharging of the battery becomes 80 carried out.

The motor generators MG1, MG2 are both of the engine ECU 300 controlled. The engine-ECU 300 For example, it receives signals necessary to drive the motor generators MG1, MG2, including signals from rotational position detection sensors 85 . 86 which detect the rotational positions of rotors of the motor-generators MG1, MG2, and phase currents which are applied to the motor-generators MG1, MG2 and detected by current sensors (not shown). The engine-ECU 300 gives control signals to the inverters 81 . 82 out.

The engine-ECU 300 communicates with the HVECU 100 and controls the drive of the motor-generators MG1, MG2 in accordance with a control signal from the HVECU 100 , The engine-ECU 300 Also, if necessary, gives data regarding the operating conditions of the motor-generators MG1, MG2 to the HVECU 100 out. The engine-ECU 300 calculates the rotational speeds Nm1, Nm2 of the motor generators MG1, MG2 on the basis of signals from the rotational position detection sensors 85 . 86 ,

The battery 80 It consists of a secondary battery, such as a nickel-hydride battery or a lithium-ion battery, which can be charged or discharged. The battery 80 is designed to supply and receive electric power to and from the motor-generators MG1, MG2. In this embodiment, the battery provides 80 the power storage device according to the invention ready.

The battery 80 is from the battery ECU 400 controlled or managed. The battery ECU 400 receives signals that are needed to the battery 80 to manage, including a voltage between the terminals of the battery 80 from a voltage sensor (not shown) installed between the terminals, of a charge / discharge current from a current sensor (not shown) in the power line 83 installed with the output terminal of the battery 80 and a battery temperature Tb from a battery temperature sensor 88 who is in the battery 80 is installed.

The battery ECU 400 Provides data related to battery conditions via communication links as needed 80 to the HVECU 100 out. In addition, the battery ECU calculates 400 the remaining capacity (SOC) based on the integrated value of the charge / discharge current detected by the current sensor to the battery 80 to manage, and calculates input and output limits Win, Wout as the maximum allowable electrical power with which the battery 80 can be charged, and the maximum allowable electrical power provided by the battery 80 For example, the input and output limits Win, Wout may be calculated by multiplying their respective temperature-dependent values based on the battery temperature Tb by a correction margin for the input limit or a correction coefficient for the battery Output limit based on the remaining capacity (SOC) of the battery 80 based, be set. The input and output limits Win, Wout may also be determined by referring to an input / output limit map in which the input / output limit Win, Wout is associated with the remaining capacity (SOC) and the battery temperature Tb.

The battery ECU 400 calculates a required charging power Pchg, which is necessary to the battery 80 on the basis of the state of charge (SOC) or the remaining capacity of the battery 80 and sets the calculated required charging power Pchg. That is, the battery ECU 400 sets the required charging power Pchg such that the remaining capacity (SOC) of the battery 80 is held at a predetermined control target (eg, a control center).

The required charging power Pchg is set to a positive value (Pchg> 0) when the battery 80 is to be charged, and is set to a negative value (Pchg <0) when the battery 80 should be unloaded. In this embodiment, when the battery 80 should be loaded, that is, when a charge request is issued, the above-described required charging power Pchg is changed according to the vehicle speed V, as described later.

The HVECU 100 is designed as a microprocessor, which is a CPU 100a as a main component, and further comprises a ROM 100b storing processing programs, a RAM 100c storing data, and input and output ports and a communication port (not shown).

An ignition switch 101 , an accelerator position sensor 102 , a vehicle speed sensor 103 and a shift position sensor 104 are with the HVECU 100 connected. The ignition switch 101 gives an ignition signal to the HVECU 100 which corresponds to an actuation by the user. The accelerator pedal position sensor 102 detects the accelerator pedal position Acc based on the amount of depression of the accelerator pedal 8th and outputs a signal indicative of accelerator pedal position Acc to the HVECU 100 out. The vehicle speed sensor 103 detects the vehicle speed V of the hybrid vehicle and outputs a signal indicating the vehicle speed V to the HVECU 100 out. In this embodiment, the vehicle speed sensor 103 the detector according to the invention ready.

The shift position sensor 104 detects the operating position (switching position SP) of the shift lever 9 and outputs a signal indicating the shift position SP to the HVECU 100 out. The shift position SP may be selected, for example, from a parking position (P position) for parking, a drive position (D position) for moving forward, a reverse position (R position) for reversing, and so on.

The HVECU 100 is with the power engine ECU 200 , the engine ECU 300 and the battery ECU 400 connected via the communication port as described above, and supplies and receives various control signals and data to and from the engine ECU 200 to or from the engine-ECU 300 and to or from the battery ECU 400 ,

In the hybrid vehicle 1 , which is constructed as described above, the total required driving force F of the vehicle is calculated on the basis of the amount of operation of the accelerator Acc and the vehicle speed V, and the engine 2 and the motor-generators MG1, MG2 are controlled so that the required power corresponding to the required driving force F is applied to the counter gear 35 is issued. For example, the HVECU 100 a needed engine power Pe coming from the engine 2 is necessarily to be generated by adding the above required charging power Pchg and a loss Loss to a value obtained by multiplying the calculated required driving force F by the rotational speed Nr of the ring gear shaft 32a is received. Likewise, the HVECU calculates 100 the engine speed and the engine torque from the thus adjusted engine power Pe using an optimum fuel consumption line.

In this connection, a map (not shown) defining the relationship between the accelerator operation amount Acc and the vehicle speed V and the required driving force F is preliminarily determined empirically and in the ROM 100b the HVECU 100 saved. The HVECU 100 can provide the required driving force F from the hybrid vehicle 1 is calculated with reference to the map based on the accelerator operation amount Acc and the vehicle speed V compute.

The driving mode of the hybrid vehicle 1 For example, it may be selected from a hybrid drive mode, an electric motor drive mode, a regeneration drive mode, and so on.

In hybrid drive mode, the hybrid vehicle is traveling 1 using both the engine 2 and the motor generator MG <b> 2 as driving power sources, while causing the motor generator MG <b> 1 to generate electric power using the output of the engine 2 generated. In the electric motor drive mode, the hybrid vehicle is traveling 1 by using the motor generator MG <b> 2 as a driving power source in a state where the engine is stopped. In the regeneration driving mode, when a certain condition, for example, a braking demand is given, the motor generator MG2 generates electric power by using energy via the transmission mechanism 60 is obtained.

Now, referring to 2 and 3 the damper device 70 described according to this embodiment.

As in 2 is shown, the damper device 70 in a power transmission path between the engine 2 and the planetary gear mechanism 3 arranged. As in 3 is shown, the damper device 70 a hub 71 , a pair of side plates 72A . 72B and a hysteresis mechanism 73 on that between the hub 71 and the side plates 72A . 72B is arranged. The hysteresis mechanism 73 serves a torque fluctuation (rotational fluctuation) of the engine 2 to absorb.

The hysteresis mechanism 73 is configured to generate a hysteresis torque having frictional force generated by a friction material (not assigned a reference numeral), a torque fluctuation (rotational fluctuation) of the engine 2 to absorb. The friction material is between the hub 71 and the two side plates 72A . 72B provided and generates a predetermined hysteresis torque when the hub 71 and the two side plates 72A . 72B rotate in relation to each other.

As in 2 shows the hysteresis mechanism 73 a first hysteresis generation section 73a which generates a first hysteresis torque depending on the torsion angle, and a second hysteresis generation section 73b which has a second hysteresis torque, the is greater than the first hysteresis torque, generated depending on the torsion angle.

The first hysteresis generation section 73a uses a material having little friction as the above-mentioned friction material. On the other hand, the second hysteresis generation section uses 73b a material with high friction than the friction material.

That is, the damper device 70 According to this embodiment, there is a so-called two-stage hysteresis damper which has two hysteresis generation sections which generate different hysteresis torques depending on the torsion angle. With this arrangement, the damping device dampens 70 by means of the two hysteresis generation sections 73a . 73b Low torque vibrations and also avoids generating excessively high torque during engine starting and stopping 2 ,

The damper device 70 also has a coil spring 75 on, which serves as a damper. Accordingly, the hub rotate 71 and the two side plates 72A . 72B over the coil spring 75 in relation to each other.

For example, in a known hybrid vehicle having the above-described two-stage hysteresis damper, if the SOC of the battery is decreased, the required charging power in the hybrid drive mode is set to a high value to charge the battery. In this case, the engine may be operated in a region where the rotational speed is low and the torque is high, so that the required charging performance can be ensured.

4 shows changes in the required charging power and engine torque when the hybrid vehicle switches from the electric motor drive mode to the hybrid drive mode.

For example, when the required charging power (= β) at the time of switching from the electric motor running mode to the hybrid running mode is large, as in FIG 4 is shown, then the change amount of the required charging power is increased, and the fluctuation range of the engine torque (in 4 indicated by a solid line) is increased accordingly.

Therefore, in the known two-stage hysteresis damper, the torsion angle is increased, and the second hysteresis torque greater than the first hysteresis torque is applied, as in FIG 5 is shown. As a result, further torsion in the hysteresis mechanism is limited and no further hysteresis can be applied. As a result, a torque fluctuation of the engine is directly applied to the planetary gear mechanism, resulting in a deterioration of the performance in the suppression of vibration and abnormal noise.

At this time, when the vehicle speed is relatively high, vibrations and abnormal noises caused by the running of the vehicle, the vibrations and abnormal noises caused by the operation of the engine in the region where the engine speed is low and the torque is high, be masked. However, when the vehicle speed is low, these vibrations and abnormal noises can not be masked.

According to the related art, in order to suppress the vibrations and abnormal noises, the engine speed is increased and the engine torque is reduced, so that the engine is prevented from being operated in the region where the engine speed is low and the engine torque is high Vibrations and abnormal sounds are likely to occur. However, when this method is used, new problems may arise such as noise caused by engine spin and deterioration in fuel economy.

Thus, in this embodiment, a control for decreasing the required charging power Pchg is performed when the vehicle speed V is in a low vehicle speed region in which it is likely that the driver will perceive vibrations and abnormal noises to improve the performance with respect to Suppression of vibration and abnormal noise to improve. The control for reducing the required charging power is provided by the battery ECU 400 carried out.

Specifically, the battery ECU leads 400 the controller for reducing the required charging power Pchg by when the vehicle speed sensor 103 (please refer 1 ) detected vehicle speed V is smaller than a predetermined or predetermined vehicle speed V1 (V <V1), so that a torque fluctuation of the engine 2 from the first hysteresis torque generated by the first hysteresis generation section 73a is generated, is absorbed.

That is, when the vehicle speed V is less than the predetermined vehicle speed V1 (V <V1), the battery ECU 400 under the control to reduce the required charging power the required charging power Pchg to a required charging power Pch_α a (see 4 ), which is lower than a required charging power Pchg_β, to which the required charging power Pchg is normally set.

The predetermined vehicle speed V1 is a vehicle speed on the basis of which it is determined whether the vehicle (ie, the vehicle driving conditions) is located in a region (referred to as "region where rattle is audible") in which the driver vibrates and abnormal Noises, especially a rattle, can hear. The vehicle speed V1 is preliminarily determined empirically and in the ROM of the battery ECU 400 saved.

6 FIG. 13 is a view showing the region where rattling is heard using the vehicle speed V and the required driving force as parameters. As in 6 is shown, a region in which the vehicle speed V is lower than the vehicle speed V1 and the required driving force F is smaller than the required driving force F1, is referred to as a region in which a rattle is audible. In a region where the vehicle speed V is at or above the vehicle speed V1, the rattle is masked by background noise. In a region where the required driving force F is at or above the required driving force F1, an engine torque Tm is generated by the motor generator MG2, so that it is less likely or unlikely that rattling of the transmission or the like which is the above called rattling caused in the planetary gear mechanism 3 or the reduction gear 4 arises.

When the vehicle speed V is lower than the predetermined vehicle speed V1 (V <V1) in this embodiment, the required charging power Pchg is uniformly set to the required charging power Pchg_α. However, the required charging power Pchg does not have to be set in this way, but may be reduced, for example, when the vehicle speed V is lower.

Now, referring to 7 the control for reducing the required charging power by the battery ECU 400 described according to this embodiment. The control for reducing the required charging power is provided by the battery ECU 400 performed at certain time intervals.

As in 7 is shown, determines the battery ECU 400 if necessary, the battery 80 to load (step S11). The battery ECU 400 can determine if it is necessary the battery 80 to charge by determining if the SOC of the battery 80 is reduced, that is, whether the SOC is at or below a predetermined value.

When the battery ECU 400 determines that it is not necessary to use the battery 80 to load, this cycle ends the routine of 7 , When the battery ECU 400 on the other hand determines that it is necessary the battery 80 to load, it determines whether the vehicle speed V is lower than the predetermined vehicle speed V1 (step S12). For example, the vehicle speed V becomes the vehicle speed sensor 103 recorded and via the HVECU 100 to the battery ECU 400 Posted.

When the battery ECU 400 determines that the vehicle speed V is not lower than the predetermined vehicle speed V1, that is, when the vehicle speed V is at or above the predetermined vehicle speed V1, then the battery ECU 400 the required charging power Pchg to a required charging power Pchg_β a (see 4 ) to which the required charging power Pchg is normally set (step S13), and this routine ends. Here, the normally set required charging power Pchg_β is the required charging power based on the SOC of the battery 80 is set as described above.

When the battery ECU 400 on the other hand determines that the vehicle speed V is lower than the predetermined vehicle speed V1, then it sets the required charging power Pchg to a required charging power Pchg_α (see 4 ), which is lower than the normally set required charging power Pchg_β, and this cycle of the routine ends.

In this way it is possible to use the engine power Pe, by the HVECU 100 is set in view of the required charging power Pchg, resulting in lowering the engine torque with which the engine power Pe is generated. In this case, the required charging power Pchg_α is independent of the SOC of the battery 80 adjusted to the engine torque, the application of the first hysteresis torque in the damper device 70 allowed to provide.

When the control for reducing the required charging power is performed in this manner, the engine torque in the region where rattle is audible, as in FIG 8th is shown, compared to the in 5 example can be reduced. As a result, the torsion angle in the damper device 70 be kept in the range of a first hysteresis torque application angle, and the first hysteresis torque can be applied against torque fluctuation. Thus, the torque fluctuation of the engine becomes 2 attenuated.

When the vehicle speed V is lower, for example, when the vehicle speed V is lower than the predetermined vehicle speed V1, the vehicle control system decreases 10 According to this embodiment, as described above, the required charging power Pchg to the required charging power Pchg_α, which is lower than the normally set required charging power Pchg_β, so that the torque fluctuation of the engine 2 is absorbed by the first hysteresis torque smaller than the second hysteresis torque. Thus, in the low vehicle speed region (eg, in the region where rattle is audible), the first hysteresis torque may be applied against the torque fluctuation.

Also in the case where the damper device 70 The shape of the two-stage hysteresis damper that generates a first hysteresis torque and a second hysteresis torque depending on the torsional angle is the vehicle control system 10 Thus, according to this embodiment, it is capable of suppressing vibration and abnormal noise caused by the operation of the engine 2 be effected under driving conditions (eg, in a region with a low vehicle speed) under which it is likely that the driver will perceive the vibrations and abnormal noises.

In the vehicle control system 10 According to this embodiment, there is no need to increase the engine speed in order to suppress vibrations and abnormal noises in the region where the vehicle speed is low (for example, in the region where rattle is audible), as in FIG the known system; Therefore, the above problems, such as a noise caused by a spin of the engine 2 caused and deterioration of the fuel consumption, can be prevented.

Now, a second embodiment of the invention will be described with reference to FIG 9 described.

This embodiment differs from the above-mentioned first embodiment in a part of the routine for the control of the required charging power reduction, but in other aspects is substantially identical to the first embodiment. Thus, components or portions similar or equivalent to those of the first embodiment are assigned the same reference numerals, and those components or portions will not be described in detail, but only a portion of the second embodiment different from the first embodiment will be described.

As described above with respect to the first embodiment, when the required driving force F is smaller than the predetermined required driving force F1, the vehicle (ie, the vehicle driving conditions) is in the region where rattle is audible. That is, when the required driving force F is smaller than the predetermined required driving force F1, the motor torque Tm of the motor generator MG2 becomes substantially zero, resulting in a condition where no torque is applied to a gear coupled to the motor generator MG2 (eg the sun wheel 41 ) is created. Therefore, it may be in the reduction gear 4 or in the planetary gear mechanism 3 Rattling of the gearbox, which can lead to a rattling noise in the vehicle.

Accordingly, under the control for reducing the required charging power of this embodiment, instead of the vehicle speed V, it is determined from the required driving force F whether the vehicle is in the region where rattle is audible, and the required charging power Pchg is changed as needed.

In the following, the control for reducing the required charging power according to this embodiment will be described. In the charging power reduction control according to this embodiment, the step of determining whether charging of the battery is performed 80 is necessary (step S11 in the first embodiment), that of the first embodiment is the same and thus will not be described.

As in 9 is shown, determines the battery ECU 400 whether the required driving force F is smaller than a predetermined driving force F1 (step S21). The HVECU 100 calculates the required driving force F based on the accelerator opening degree Acc and the vehicle speed V, and the battery ECU 400 receives the thus calculated required driving force F from the HVECU 100 , The default drive force F1, which provides a basis for determining if the vehicle is in the region where rattle is audible (see 6 ), is determined in advance empirically and in the ROM of the battery ECU 400 saved.

When the battery ECU 400 determines that the required driving force F is not smaller than the predetermined required driving force F1, that is, if the required driving force F is at or above the predetermined required driving force F1, the battery ECU will stop 400 the required charging power Pchg to the normally set required charging power Pchg_β (see 4 ) (step S22), and this cycle of the routine of 9 ends. Here, the normally set required charging power Pchg_β is the required charging power based on the SOC of the battery 80 is set as described above.

When the battery ECU 400 on the other hand determines that the required driving force F is smaller than the predetermined required driving force F1, it sets the required charging power Pchg on the required charging power Pchg_α (see 4 ) which is lower than the normally set required charging power Pchg_β (step S23), and this cycle of the routine ends.

When the required driving force F is lower, for example, when the required driving force is lower than the predetermined required driving force F1, the vehicle control system decreases 10 According to this embodiment, as described above, the required charging power Pchg to the required charging power Pchg_α, which is lower than the normally set required charging power Pchg_β, so that the torque fluctuation of the engine 2 is absorbed by the first hysteresis torque smaller than the second hysteresis torque. Thus, in the low vehicle speed region (eg, in the region where rattle is audible), the first hysteresis torque may be applied against the torque fluctuation.

Also in the case where the damper device 70 The shape of the two-stage hysteresis damper that generates a first hysteresis torque and a second hysteresis torque depending on the torsional angle is the vehicle control system 10 Thus, according to this embodiment, it is capable of suppressing vibration and abnormal noise caused by the operation of the engine 2 be effected under driving conditions (eg, in a region with a low vehicle speed) under which it is likely that the driver will perceive the vibrations and abnormal noises.

With the vehicle control system 10 According to this embodiment, the above-mentioned problems, for example, a noise caused by a spin of the engine 2 and deterioration of the fuel consumption values are prevented as in the first embodiment.

When the required driving force F in this embodiment is lower than the predetermined driving force F1 (F <F1), the required charging power Pchg is set uniformly to the required charging power Pchg_α. However, the required charging power Pchg does not necessarily have to be set in this manner, but may be reduced, for example, when the required driving force F is lower.

Under the control for decreasing the required charging power of this embodiment, instead of the vehicle speed V, it is determined from the required driving force F whether the vehicle (ie, the vehicle driving conditions) is in the region where rattle is audible, and the required charging power Pchg becomes low Changed needs. However, this invention is not limited to this arrangement, but it can be determined from the vehicle speed V and the required driving force F whether the vehicle is in the region where rattling is heard, and the required charging power Pchg can be changed as required become. In this case, the region in which a rattle is heard can be more appropriately or more accurately specified, and the control for reducing the required charging power is prevented from being unnecessarily performed.

Now, a third embodiment of the invention will be described with reference to FIG 10 described.

This embodiment differs from the above-mentioned first and second embodiments in a part of the routine of the required charging performance reduction control, but in other aspects is substantially identical to the first embodiment. Thus, components or portions that are the same as or correspond to the first and second embodiments are assigned the same reference numerals, and these components or portions will not be described in detail, but only a portion of the second embodiment, which is different from the first embodiment, described.

In the second embodiment described above, under the control for reducing the required charging power from the required driving force F, it is determined whether the vehicle is in the region where rattle is audible, and the required charging power Pchg is changed as needed. In this embodiment, it is determined whether the vehicle (i.e., the vehicle traveling conditions) is in a region where the engine torque Tm of the motor generator MG2 is substantially equal to zero, and the required charging power Pchg is changed as necessary.

In the following, the control for reducing the required charging power according to this embodiment will be described. In the charging power reduction control according to this embodiment, the step of determining whether charging of the battery is performed 80 is necessary (step S11 in the first embodiment), that of the first embodiment is the same and thus will not be described.

As in 10 is shown, determines the battery ECU 400 whether the absolute motor torque | Tm | of the engine torque Tm is smaller than a predetermined engine torque Tm1 (step S31). That is, the battery ECU 400 determines whether the motor torque Tm of the motor generator MG2 is greater than a predetermined motor torque -Tm1 and less than a predetermined motor torque Tm1. That is, the battery ECU 400 determines whether the engine torque Tm is in a predetermined torque range including a torque of zero (Tm = 0). The engine torque Tm is determined by the engine-ECU 300 via the HVECU 100 to the battery ECU 400 cleverly.

For that matter, the predetermined engine torque Tm1 is set to a torque amount (eg, 1 Nm) on the basis of which it can be determined that no torque from the motor generator MG2 to the sun gear 41 is created. The predetermined engine torque Tm1 is preliminarily stored in the ROM of the battery ECU 400 or in ROM 100b the HVECU 100 saved.

The engine torque Tm can be derived, for example, from the following equation (1). In the following equation (1), F is the required driving force [N] of the hybrid vehicle 1 , Tm is the motor torque [N · m] of the motor generator MG2, Gr is the reduction ratio of the reduction gear 4 , Te is the engine torque [N · m], p is the planetary teeth number _ratio , ρ _def is the differential _{ratio of} the differential gear, and Rt is the diameter of the tire [m]. F = {(TmxGr) + Tex (1/1 + ρ)} xρ _def / Rt (1)

If the battery ECU 400 determines that the engine torque Tm is not smaller than the predetermined engine torque Tm1, that is, the engine torque Tm is at or above the predetermined engine torque Tm1, the battery ECU 400 the required charging power Pchg to the normally set charging power Pchg_β (see 4 ) (Step S32), and this cycle of the routine of 10 ends. Here, the normally set required charging power Pchg_β is the required charging power based on the SOC of the battery 80 is set as described above.

If the battery ECU 400 on the other hand determines that the engine torque Tm is smaller than the predetermined engine torque Tm1, then sets the required charging power Pchg to the required charging power Pchg_α (see 4 ), which is lower than the normally set required charging power Pchg_β (step S33), and this cycle of the routine ends.

If the engine torque Tm is less than the predetermined engine torque Tm1, then the vehicle control system decreases 10 According to this embodiment, as described above, the required charging power Pchg to the required charging power Pchg_α, which is lower than the normally set required charging power Pchg_β, so that the torque fluctuation of the engine 2 is absorbed by the first hysteresis torque smaller than the second hysteresis torque. Thus, in the low vehicle speed region (eg, in the region where rattle is audible), the first hysteresis torque may be applied against the torque fluctuation.

Also in the case where the damper device 70 has the shape of the two-stage hysteresis damper is the vehicle control system 10 Thus, according to this embodiment, it is capable of suppressing vibration and abnormal noise caused by the operation of the engine 2 be effected under driving conditions (eg, in a region with a low vehicle speed) under which it is likely that the driver will perceive the vibrations and abnormal noises.

In each of the above embodiments, the vehicle control system according to the invention is the hybrid vehicle 1 installed in which the engine 2 and the motor generators MG1, MG2 via the power distribution / integration mechanism 3 and the reduction gear 4 are connected. However, the invention can be applied to other types of hybrid vehicles, provided that the hybrid vehicle has two electric motors, such as the motor-generators MG1, MG2, and the damper device 70 having. More specifically, a mechanism having these power output and input devices (internal combustion engine and motor-generators MG1, MG2) can be constructed in other ways. As described above, the vehicle control system according to the invention is capable of performance in suppressing vibrations and abnormal noises generated by operation of the engine under driving conditions under which it is likely that the driver will perceive the vibrations and abnormal noises. Thus, the vehicle control system of the invention is suitable as a control system used in a hybrid vehicle.

Claims (3)

Control system for a hybrid vehicle, comprising: an internal combustion engine; a generator that receives power or generates power; a planetary gear mechanism having three rotary elements connected to an output shaft of the internal combustion engine, a rotary shaft of the generator, and a drive shaft connected to drive wheels, respectively; an electric motor that receives power from the drive shaft or generates power for the drive shaft; a power storage device that supplies and receives electric power to and from the generator and the electric motor; a damper device disposed in a power transmission path between the internal combustion engine and the planetary gear mechanism, the damper device having a hysteresis mechanism that generates a hysteresis torque with a friction force generated by a friction material; a detector detecting a vehicle speed of the hybrid vehicle; and an electronic control unit configured to set a required electric power necessary to charge the power storage device based on a state of charge of the power storage device, the electronic control unit configured to reduce the required electric power, when the vehicle speed detected by the detector is lower, so that a rotational fluctuation of the output shaft of the internal combustion engine is absorbed by the hysteresis torque generated by the hysteresis mechanism. A control system according to claim 1, wherein the hysteresis mechanism has a first hysteresis generating section that generates a first hysteresis torque depending on the torsion angle of the damper device and a second hysteresis generating section that generates a second hysteresis torque larger than the first hysteresis torque depending on the torsion angle; and the electronic control unit is configured to reduce the required electric power when the vehicle speed detected by the detector is lower, so that the rotational fluctuation is absorbed by the hysteresis torque generated by the first hysteresis generation section. A control system according to claim 2, wherein the electronic control unit is configured to calculate a required driving force required by the vehicle; and the electronic control unit is configured to reduce the required electric power when the calculated required driving force is lower, so that the rotational fluctuation is absorbed by the hysteresis torque generated by the first hysteresis generating section.

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